1. Field of the Invention:
This invention relates to an air conditioner for a vehicular seat.
2. Description of Prior Arts:
In a vehicle driven in a cold district or during the winter, since the temperature of the interior thereof is low, the interior or the seat is warmed to improve the comfort of ride. The warming of the seat, for example, is effected by using a heater connected to the vehicle's power source and embedded in the seat or by sending a current of warm air to the seat from an air heater suitably disposed in the interior.
When the heater connected to the vehicle's power source is used for the warming, however, it consumes a large volume of energy from the power source such as a car battery and proves uneconomical in spite of the advantage that the temperature of the heater is instantaneously elevated to bring the temperature of the seat quickly to the preset temperature when the switch is closed to turn on the heater.
The air heater is designed to warm air by making use of the heat of the engine cooling water. This air heater used for warming the seat, therefore, proves economical. It nevertheless suffers from the disadvantage that since the temperature of the engine cooling water is low during the initial stage of the engine operation and further since the elevation of the seat temperature by the current of warm air occurs with poor efficiency, the seat temperature is elevated at a low rate and requires much time before it reaches the predetermined level.
When the vehicle is driven in a hot district or during the summer, the interior thereof, particularly the seat installed therein, must be cooled for the sake of the comfort of ride.
To ensure preservation of good environment in automobile interiors, most automobiles have been provided with devices for cooling, warming or air conditioning their interior spaces. These devices are preponderantly air conditioners. Despite the use of such devices, in the vehicle driven in a hot district, the driver sitting on the seat perspires on the back and the hips so much as to spoil the comfort of ride no matter how much the space may be cooled and, in the vehicle driven in a cold district, the driver finds that the seat is so cold and it won't warm up readily no matter how much the space may be warmed.
One of the present inventors formerly developed a cushioning material high pervious to air (U.S. Pat. Nos. 4,172,174, 4,298,418 and 4,386,041 and U.S. Ser. No. 292,907). One of his inventions covering this cushioning material relates to a reinforced cushioning material comprising a compression molded body of drafted three-dimensionally crimped filament mass of a synthetic fiber in which the crimped filaments are of staple length and randomly-oriented and the contact points between each of the filaments are bonded with an adhesive, said body having isolated zones in which the crimped filament is further crimped in situ into various shapes formed by partially expanding and compressing the filament crimps in said zones, and said zones being distributed throughout the reinforced portion of said body, being oriented in the same direction, and having increased density in the degree of entanglement and the number of contact points.
By taking notice of the fact that this cushioning material, used in the vehicular seat, exhibits high perviousness to air, the inventor further developed a seat capable of being air conditioned with cool air or warm air introduced into the interior of the seat (Published unexamined Japanese Utility Model Application No. SHO 55(1980)-148,449, Nos. SHO 57(1982)-90,661 through 90,664, Nos. SHO 57(1982)-142,945 through 142,946 and No. SHO 57(1982)-146,558).
In average human beings, the body temperature is 37.degree. C. and the skin temperature is 30.degree. to 34.degree. C. It is beyond at least 35.degree. C., preferably at least 40.degree. C. that warmth of the ambient air is perceived. When the temperature of the ambient air exceeds 50.degree. C., however, hotness rather than warmth is perceived. In a hot district, it is below 25.degree. C. that coolness is perceived. When the temperature of the ambient air falls below 10.degree. C., however, biting cold rather than coolness is perceived possibly to the extent of adversely affecting the health. In a district of meteorologically cold weather, there are places where the temperature of the ambient air falls below minus 20.degree. C. Under the condition, the system for warming the seat with the current of hot air from the air conditioner is ineffective until the engine is heated and consequently the engine cooling water is warmed to a level beyond at least 60.degree. C., preferably near 80.degree. C. Besides, the thermal energy is lost en route from the position the heat is collected to the position the heat is released. Thus, some tens of minutes' time is required for the temperature of the seat to be elevated from the level far below zero to the level of about 40.degree. C. at which the seat is desired to be maintained during its actual service. From this particular point of view, therefore, the method which heats the seat directly with an electric heater much less susceptible of energy loss proves more advantageous in respect of quick manifestation of effect.
In a district of intense heat, a cooler incorporated in the air conditioning system enables the temperature of the seat and its immediate vicinity to be lowered to the comfortable level in a matter of several minutes (less than 5 minutes, for example) even under the worst condition, because this cooler starts sending forth cool air as soon as the switch is closed and because the difference between the prevalent ambient temperature and the comfortable seat temperature desired is not very large.
An object of this invention, therefore, is to provide a novel air conditioner for the vehicular seat.
Another object of this invention is to provide an economical air conditioner for the vehicular seat, economical in the sense that it is capable of enabling the temperature of the seat to be elevated quickly to the prescribed level and reducing power consumption.